Yes, they are reef safe, need a big (BIG, at least 200 gallons) tank, and are notoriously difficult to get established. Definitely one of the hardest 3 tangs to keep in captivity IMO.
Clown and Sohal tangs are very similar and closely related. Both need a minimum of about 300gallons anything smaller is pushing it since they can get very territorial and even destructive. I know of 1 Sohal that had been housed in a 400 and would wait for someone to walk up to the tank to start knocking corals over. They both get really big even for a 300. The only tangs I would really put in a 70 would be Bristletooth type tangs (chevrons, koles, golden blue eyed, lavender, blue stripe, etc.) they will stay relatively small and will help keep the rocks clear of debris and algae.
Actually Convict tangs are very easy to keep. The problem with them in the past was that very few would show up and the ones that did were in very bad condition. This has changed over the last year as the ones that have been coming in were in very condition. They will eat just about anything and very peaceful.
I have a convict for almost a year now, I think they are fairly easy. I have had soho thru out the last 7 years, only lost one to a clown tang' blades, they are much easier than Clown tangs due to better stocks from the red sea.
I tried Achilles few times and was never successful in keeping them longer then 3 months.
I have an Achilles for about 3 years, and it was very aggressive. I lost it when the old women above me left the sink on and it flood her apartment. The water, with stuff from the ceiling, came down right on top of my tanks. I lost a lot of fish from it.
I think some of the hardest to keep tangs are the PBT and the Mimic tangs. The Mimic usually are very thin and highly stressed out. PBT are just tough to keep with more dying then making it.
Wow , that is a beauty. Guess you would would not recommend a small one into a 70 gallon, Sorry LFS Marine dont mean to 2nd guess you, btw I need to speak w/you.
I had a 2" clown tang for about 4 months, ate really well until my old tank sprung a leak and had to transfer everything over to a new tank.
That was when it started to go downhill.
I read someplace that they are reef safe to a degree, they become destructive only because of their sheer size and bulk.
Kinda like having a Mac truck in your reef tank.